Up to now, a variety of vehicle air conditioning units that blow an air conditioning wind have been known. For example, one of the vehicle air conditioning units is disclosed in Patent Literature 1. The vehicle air conditioning unit of Patent Literature 1 includes an air conditioning case, an evaporator functioning as a cooler that cools an air flowing into the air conditioning case, and a heater core functioning as a heater that heats the air flowing out of the evaporator.
The air conditioning case includes a partitioning member for partitioning an inside of the air conditioning case along an airflow direction, and a first airflow passage and a second airflow passage which are juxtaposed to each other are provided in the air conditioning case by the partitioning member. A heater core is disposed to extend across the first airflow passage and the second airflow passage. Each of the first airflow passage and the second airflow passage includes a cold air passage for allowing a cold air from the evaporator to bypass the heater core outside of the heater core.
The vehicle air conditioning unit in Patent Literature 1 includes an air mixing door that opens or closes a flow channel flowing into the heater core and the cold air passage in the first airflow passage. The same air mixing door is provided in the second airflow passage. Each of the air mixing door of the first airflow passage and the air mixing door of the second airflow passage is disposed in the air flow upstream side with respect to the heater core. In other words, each air mixing door of the first airflow passage and the second airflow passage is structured to block a lateral portion of the heater core on the upstream side when cutting off the air flow toward the heater core.